February 04, 2016. EN. Nevado Del Ruiz , Sabancaya , Karangetang , Santiaguito .
February 04, 2016.
Nevado Del Ruiz, Colombia :
The level of activity continue at level: Activity level Amarillo or (III): changes in the behavior of the volcanic activity. Regarding the monitoring of the activity of the Nevado del Ruiz volcano, the Colombian Geological Service reports that: During the last week, the volcanic system continued to show unstable behavior. The recorded seismic activity is mainly associated with the fracturing of the rock in the volcanic structure. This type of seismicity was located in the distal areas of the North over the volcano and dispersed to a lesser extent in the Southeast , Northeast and Northwest areas compared to the Arenas crater.
The depth of earthquakes during the week was between 1.1 and 8.7 km. The maximum value recorded was magnitude 0.9 ML (Magnitude Locale), corresponding to an earthquake occurred on January 28 at 01:00 (local time), located in the distal northern sector at a depth of 3.2 km .
Seismic activity related to fluid dynamics inside volcanic conduits, was characterized by the appearance of several episodes of continuous tremor and earthquakes long period (LP). These two signals are mainly located near the Arenas crater and southern – Southeast sector of the volcano. The continuous tremor signal had varying levels and low energy. Do not rule out that new episodes of increased levels of this signal and the output of gas and ash in the atmosphere can reproduce. These processes were accompanied by temperature anomalies, low to moderate as monitoring by satellite images provided by the system Mírová, from Italian universities of Turin and Florence highlighted. These moderate thermal anomalies on 27 and 31 January and 1 February, were identified near the Arenas crater, confirming the instability of the volcano.
The volcanic deformation measured from electronic inclinometers, satellite global navigation systems (GNSS) and satellite images, which record changes in the tilt, the position and shape of the volcano (respectively) during the last period evaluated, showed no significant changes.
The volcano continues to emit into the atmosphere of significant amounts of water vapor and gases, including sulfur dioxide (SO2), as has been estimated by the permanent stations SCAN DOAS installed in the volcano area and by satellite imagery.
The column of gas, steam and ash reached a height of 850 meters above the summit of the volcano on January 26. The direction of the dispersion of the column is in line with the prevailing wind in the area, which during the week showed a predominant direction towards the northwest over the volcano.
It is considered that the volcanic system continues to evolve and no new events that would indicate an acceleration of the process, involving greater instability of it .Therefore there is no change in the level of activity. While the instability of the volcano drags for more than five years, it is essential not to get used to a apparently monotonous behavior of the volcano and monitoring official information to be published by the Colombian Geological Service.
Source : SGC.
Photos : Milton H Arias , SGC.
Sabancaya , Peru :
LP type Earthquakes (associated with the passage of fluids), during this period, have declined slightly on average 15 LP / day, while in the previous period it was recorded 18 LP / day. Moreover, their energy was low.
In this period there was no hybrid type of event (associated with the rise of magma material). Earthquakes VTPS (proximal volcano-tectonic), less than 6 km from the volcano, have maintained the same average as the previous year, recording 20 VTPS / day in the last week. The extent of VTPS increased to 3.9 ml and 4.0 ml; These events were recorded on 31 and 29 January, respectively. The earthquakes type tremor were steady , registering a rate similar to the previous period (11 TRE / day on average). However, there has been a significant increase in their energy, registered on 28 January, which reached a total value of 2701 MJ that day. This large increase in power was caused by an earthquake recorded at 12:36 UTC.
VT localized events (associated with rock fracturing) persist in the area very near the Sabancaya . In this period, there were a total of 133 VT, distributed to form a single group in North-East. 93 VTP events (called proximal) situated in a radius less than 6 km have been registered. Earthquakes are distributed primarily in North-East compared to the crater. Among these VTP, we must emphasize two important events of magnitude 3.9 and M M4,0, recorded on 29 and 31 January at 10:51 UTC and 4:06 p.m. hours respectively, with depths between 9 and 11 km.
Seismicity VTD (distal seismicity) reached a total of 40 events, and is mainly distributed in the Northeast region of the volcano’s crater. ML 3.9 event stands out, recorded on January 30, 2016 at 4:03 p.m. UTC at a depth of about 9 km.
Water vapor emissions remain constant, with a density between medium and high. During some parts of the day, it was not possible to visualize due to the weather in the region, mainly 31 January and 1 February.
Their staining was observed whitish (water vapor). Sporadic bluish emissions (magmatic gases) were observed.
The height of the fumaroles in this period (January 26 to 1 February), varied between 400 and 1200 meters above the base of the crater, approximately.
SO2 anomalies: The satellite system « EOS Aura » GSDM–NASA (http://so2.gsfc.nasa.gov/) shows a slight increase in the density of SO2.
Thermal anomalies: The Mirova system (www.mirovaweb.it) has not detected by thermal anomalies on the Sabancaya.
Source : IGP
Photos : Losviajesdeali , Actulatinos .
Karangetang , Indonesia :
Seismicity of Karangetang, during the period from 27 January to 3 February 2016 showed shallow volcanic earthquakes (VB) and tremor phases. The number of shallow volcanic earthquakes (VB) showed an increase, and is between 2 to 13 episodes per day. Many earthquakes indicating cracking of rock (lava dome) increased. If we look at the energy of volcanic earthquakes during the period from 27 January to 3 February 2016she did not show significant improvement
Volcanic activity around the eruption of the lava dome has not wavered. The earthquake tremor type and spasmodic tremor yet often recorded with maximum amplitude ranging around 0.5 mm, so that effusive eruptive activity will likely take place. The RSAM data increased on 8 September 2015, and then gradually decreased until November 6, 2015 and has seen an increase in return on December 18, 2015. During January 2016, the 2-fold increase in energy RSAM was influenced by an increase of shallow volcanic earthquakes (VB) until 26 January 2016.
Currently, the eruption of Karangetang is potentially effusive (lava flows) and pyroclastic avalanches (incandescent lava). We must remember the explosive eruptions as happened in September 2013 during which the top has been formed an unstable lava dome, making it easily destructible. Pyroclastic avalanches could occur when the lava dome that accumulates becomes unstable. Higher rainfall could trigger avalanches, especially in Kali Batuawang , Kali Keting and Kali Kahetang .
The results of the data analysis and visual and instrumental evaluations until February 3, 2016 18:00 have not shown an increase / decrease of major volcanic activity, so it is concluded that the level of activity of Karangetang remains at level III (SIAGA).
The level of activity will be reduced / increased again if there is a decrease / increase in volcanic activity and will be adapted to the level of the threat.
Source : VSI
Photos : theatlantic.com , VSI .
Santiaguito, Guatemala :
Elevation 3772 m
INSIVUMEH reported that during 29 January-1 February explosions from Caliente cone, part of Santa María’s Santiaguito lava-dome complex, generated ash plumes that rose 600-800 m and drifted E, SE, and SW. Ashfall was reported in Monte Claro (S), San Marcos (10 km SW), Palajunoj (18 km SSW), Aldea, and Santa María de Jesús. Small avalanches were generated from active lava flows.
Source: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia, e hidrología (INSIVUMEH)
Photo : http://expertvagabond.com